Final answer:
Thermodynamic variables, such as pressure, volume, temperature, and amount of gas, directly impact the properties of gases, defining dependencies like volume's increase with temperature.
Step-by-step explanation:
The variables that directly impact the properties of gases are known as thermodynamic variables. These include pressure, volume, temperature, and the amount of gas (often measured in moles). When considering the nature of an ideal gas, these variables are essential in understanding and predicting how a gas will behave under various conditions.
Dependent variables in gas behavior are typically properties like volume or pressure that change as a result of changes in explanatory variables like temperature. Explanatory variables, on the other hand, are those that cause changes in the dependent variables. For example, if temperature is increased and the amount of gas and its pressure are held constant, the volume will increase, demonstrating a direct relationship between temperature and volume. In thermodynamic systems, such as a sample of gas, the relationship between these variables is described by an equation of state, such as the ideal gas law.